Background: Adjuvant or neoadjuvant chemotherapy increased 5% survival compared with surgery alone for completely resected stage II-IIIa NSCLC. No significant difference in overall survival among adjuvant vs neoadjuvant vs surgery was found in NATCH study. Clinical issue is how to select adjuvant or neoadjuvant therapy for resectable NSCLC. Methods: Patients with stage IB-IIIA NSCLC were eligible. Adjuvant or neoadjuvant chemo regimen was designed as 3 cycles DC (Docetaxel: 75mg/m2, Carboplatin:AUC = 5 on day 1 every 3wks). The primary end point was 3yrs disease Free Survival (DFS) rate; secondary end points were 3yrs and 5yrs Overall Survival (OS) and Safety. The trial was closed early due to stage IB was not eligible since 2008 and slow accrual. The preliminary results were reported at 2013 ASCO & 2016 ESMO. Results: 214 patients were screened from 13 sites from March 2006 to May 2011, 198 patients were randomized. 97 were assigned to neoadjuvant (N) arm and 101 to the adjuvant (A) arm. Stage Ib, II and IIIa were 32.5%, 40.6% and 26.9%, respectively. 100% cases received neoadjuvant chemo and 85.1% completed the planned adjuvant chemotherapy. ORR was 34% and 12.4% patients developed PD in N arm. The 3yrs DFS rate was 53.4% (A) vs 40.2% (N) with HR 0.52 (95% CI 0.30–0.91), p = 0.033. 5yrs DFS rate was 47.9% vs 29.9%, HR 0.42 (0.24–0.75), p = 0.005. Median DFS 4.8 vs 2.1 yrs with HR 0.69 (0.48–0.98), p = 0.036. 5yrs OS was 57.8% vs 42.1%, HR 0.48 (0.27–0.85), P = 0.0143. Median OS 7.1 vs 4.2 yrs, HR 0.73 (0.50–1.07), p = 0.104. For stage II and IIIa subgroup 3yrs DFS rate was 49.3% vs 33.3% with p = 0.031, HR 0.43 (0.21–0.87), p = 0.031. 5yrs OS was 49.7% vs 40.7%, HR 0.60 (0.30–1.19), p = 0.142. Median OS 5.2 vs 3.6 yrs, HR 0.83 (0.53–1.30), p = 0.414. Recurrence model was similar between the two arms. 41.2% patients experienced grade 3-4 neutropenia. One chemotherapy related death in A arm.One patient died of perioperative pulmonary embolism in N arm. Conclusions: The 5-yrs DFS and OS of CSLC 0501 showed arm A was superior to arm N. Adjuvant chemotherapy or neoadjuvant with docetaxel plus carboplatin are feasible and safe in resectable clinical stage IB-IIIA NSCLC. Clinical trial information: NCT00321334